/* Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.activiti.engine.impl.scripting;

import org.activiti.engine.ActivitiException;
import org.activiti.engine.ActivitiIllegalArgumentException;
import org.activiti.engine.impl.persistence.entity.ExecutionEntity;
import org.activiti.engine.impl.persistence.entity.TaskEntity;
import org.activiti.engine.impl.pvm.runtime.ExecutionImpl;
import org.flowable.variable.api.delegate.VariableScope;

/**
 * Bindings implementation using an {@link ExecutionImpl} as 'back-end'.
 * 
 * @author Tom Baeyens
 * @author Joram Barrez
 */
public class VariableScopeResolver implements Resolver {

    protected VariableScope variableScope;
    protected String variableScopeKey = "execution";

    public VariableScopeResolver(VariableScope variableScope) {
        if (variableScope == null) {
            throw new ActivitiIllegalArgumentException("variableScope cannot be null");
        }
        if (variableScope instanceof ExecutionEntity) {
            variableScopeKey = "execution";
        } else if (variableScope instanceof TaskEntity) {
            variableScopeKey = "task";
        } else {
            throw new ActivitiException("unsupported variable scope type: " + variableScope.getClass().getName());
        }
        this.variableScope = variableScope;
    }

    @Override
    public boolean containsKey(Object key) {
        return variableScopeKey.equals(key) || variableScope.hasVariable((String) key);
    }

    @Override
    public Object get(Object key) {
        if (variableScopeKey.equals(key)) {
            return variableScope;
        }

        return variableScope.getVariable((String) key);
    }
}
